PB2006: CHARACTERISTICS AND OUTCOMES OF PATIENTS WITH PLASMA CELL LEUKEMIA (PCL): A SINGLE-CENTER STUDY FROM TUNISIA
Authors: Y. Fakhfakh, F. Kammoun, O. Kassar, F. Kallel, M. Chaari, N. Louati, L. Torjeman, M. Charfi, I. Frikha, I. Ben Amor, L. Khalifa, M. Medhafar, S. Hadiji, H. Elleuch, H. Mnif, T. Ben Othman, M. Elloumi
Journal: HemaSphere (2022)

Background: Plasma cell leukemia (PCL) is a rare form of leukemia and plasma cell dyscrasia defined by the presence of greater than 2×109/L peripheral blood plasma cells or plasmacytosis accounting for more than 20 % of the differential white cell count. PCL can be divided into primary PCL (PCL) and secondary PCL (sPCL) following previously diagnosed multiple myeloma (MM). It has an aggressive clinical course. Aims: In this study, we aim to identify the main clinical and laboratory disease findings, treatment patterns, and evolution in patients with PCL in a Tunisian center. Methods: Our study is a review of all cases of PCL, diagnosed and treated between 2000 and 2021 at the hematology department of the hospital of Sfax, Tunisia. Results: Nine cases of PCL were identified: 8 primary PCL cases, and only one sPCL case. The mean age was 53 years [range 31-64], and there was a female predominance (6:3). Most presenting symptoms were bone pain noted in 5/9 patients, asthenia in 3/9 patients, and bleeding was noted in only one case. Physical examination revealed extramedullary involvement in 4 patients: 2 had splenomegaly, one had hepatomegaly and one had lymphadenopathy. None of our cases showed skin infiltrates. Standard radiologic surveys showed bone osteolysis in all 9 patients, generally in the skull, and MRI showed epidural space infiltration and spinal cord compression in 2 patients. Normocytic, normochromic anemia was noted in almost all patients with mean hemoglobin of 6.9 g/dl. Rouleaux formation and a leukoerythroblastic picture were evident on almost all the peripheral blood smears. The mean leukocytosis was 15.3x109/l [range 3.4-100] and consisted of 20% to 88% of plasma cells. Thrombocytopenia with platelets < 100x109/l occurred in 50% of patients. Immunophenotyping by flow cytometry was done only in 2 cases with difficult morphology and showed expression of CD38 and CD138. Hypercalcemia was noted in almost all patients (8/9), and renal failure was present in 4 cases. Immunofixation revealed an even distribution between IgG and IgA, and light chain in 3 cases. The frequency of the Kappa chain was higher. Serum albumin levels were low in all patients. For treatment, 4 patients received VTD (Bortezomib, Thalidomide, and Dexamethasone), 2 received VAD (Vincristine, Adriamycin, and Dexamethasone), 2 were on Thalidomide Dexamethasone, and one patient received Revlemid Dexamethasone. Only one patient of these four patients who received VTD underwent autologous stem cell transplant (ASCT) after attaining CR but relapsed after 2 years into multiple myeloma and is currently in PR receiving MPT. All other patients died of progressive and refractory disease. The median survival was 9 months with a duration ranging from 2 to 63 months. Summary/Conclusion: As reported internationally, our study showed that patients with PCL were younger than myeloma patients, and presented with more aggressive clinical and laboratory features at diagnosis especially more bone lesions than classically described, and a high frequency of hypercalcemia. Besides, it indicated that even after the use of novel drugs, response to treatment is poor and PCL still has a poor prognosis.